Question

I used the instruments tool and it tells me I have no memory leaks. But I am struggling with the logic behind it. Why wouldn’t this be leaky? It appears that some magic is happening behind the scenes and my AppDelegate is using my allocated navController to set the property of the self.navigationController. Without my initialization here, my property is nil.
Shouldn’t I be forced to make these instance variables of the delegate and then release them in the dealloc? Why isn’t this a leak? Or am I using the instruments tool wrong?

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 

      // two alloc calls which would imply I need a release 
  UINavigationController *navController = [[UINavigationController alloc] init];
  UIViewController *calcController = [[CalculatorViewController alloc] init];

  [navController pushViewController:calcController animated:YES];

  [window addSubview:navController.view];
  [window makeKeyAndVisible];

      // can not release here, if i do, no views show up
      // [navController release];
      // [calcController release];

      return YES;
}
...
// NOTE: No dealloc for navController or calcController
- (void)dealloc {
   [window release];
   [super dealloc];
}

Answer 1

Both navController and calcController exist for the life of the program. When the program terminates, everything is purged, so it doesn’t matter. You do have a leak, but an irrelevant one.